The 10 Weirdest Objects in the Universe

The El Gordo Galaxy Cluster

In a place as big as the universe, there’s bound to be some weird stuff. Here we present the biggest, coldest, hottest, oldest, deadliest, loneliest, darkest, brightest, and more superlatives that the cosmos has to offer, ranging from right next door to the edge of the known universe.

First up, El Gordo. Spanish for “the fat one,” El Gordo is the most massive grouping of galaxies in the distant universe. It contains 3,000,000,000,000,000 (3 million billion, but who’s counting?) times as much mass as the sun.

El Gordo is located 9.7 billion light-years from us, which means it had already grown this large when the universe was just half its current age.

The Black Widow Pulsar

Pulsar J1311-3430 is a dangerous partner to have.

It weighs as much as two suns but is only as wide as Washington, DC — and it's getting bigger by feeding off its mate, a normal star. The two pirouette around each other every 93 minutes in a deadly, close dance.

The pulsar’s beam strips layers away from the star, which the pulsar then slurps up. That extra material gives the pulsar more energy, making it spin even faster, but leaving its partner depleted. So depleted that someday, nothing will be left and the pulsar will dance with only itself.

3753 Cruithne

A year on this asteroid (364 days) is almost exactly the same as a year on Earth, meaning they both orbit the sun at about the same distance. Nobody knew about our orbit-twin until 1986, when Duncan Waldron discovered it.

But don’t worry about a collision: Cruithne won’t come closer than 7.5 million miles from Earth. If you want to run a cosmic 5K, though, you can do it across this rock’s surface, which is 3.1 miles in diameter.

Smith's Cloud

If your eyes could see radio waves, Smith’s Cloud would show up 20 times as wide as the full moon in the night sky.

This cloud of hydrogen gas has as much mass as one million stars, but that hydrogen spreads over an area 9,800 light-years long by 3,300 light-years wide.

It looks like a torpedo, and that’s a helpful way to think about it too: It’s headed for our galaxy and will crash into the Milky Way 27 million years from now. That infusion of high-velocity hydrogen could set off fireworks of star formation.

Galaxy X

Three hundred thousand light-years beyond the Milky Way orbits a satellite galaxy made almost entirely of dark matter and gas — with hardly any stars at all.

Astronomers had suspected its existence for years, but it’s hard to find “dark galaxies” in the darkness of space. In 2009, astronomers detected evidence of "Galaxy X" in the form of ghostly ripples in our own galaxy’s disk. Then, this year, they managed to find four 100-million-year-old stars hiding in this distant clump of dark matter.

HD 189733b

This planet’s blue hue might call to mind peaceful oceans and pleasant summer days. But don’t be fooled. It’s a huge gas giant orbiting close to its star, which would makes it a hellish place to live, for a few reasons:

a) No oceans exist ever, b) the temperature rockets as high as 1,700 degrees Fahrenheit, and c) the apparent azure sky actually comes from a deadly weather pattern: rain made of molten glass.

The Biggest Old Black Hole

When the universe was just 875 million years old (a mere babe), a black hole with the mass of 12 billion suns had already formed.

For reference, the one at the center of the Milky Way, shown here, is just 4 million times the sun’s mass.

Supermassive J0100+2802 sits at the center of an active galaxy, called a quasar, 12.8 billion light-years away. But how could something become so big at such a young age? Astronomers are still working that out.

The Boomerang Nebula

Pack a jacket before taking the 5,000 light-year trip to the Boomerang Nebula: This is the coldest thing in the universe.

Inside this cloud of gas and dust cast off from a dying sun-sized star, the mercury rises to just -458 degrees Fahrenheit. The cloud is expanding at around 367,000 miles per hour, or 10 times as fast as the fastest man-made object in the universe, the New Horizons spacecraft, is traveling.

That expansion chills the nebula's gas in the same way that ballooning tetrafluoroethane cools your refrigerator.